Composite structural material with diffusion barrier layer, especially for slide and friction members, and method of manufacture

摘要

A composite structural material particularly intended for frictional and slide elements, consisting of a substrate such as a steel layer with a copper- or tin-containing intermediate layer, a tin- or copper-containing functional layer and, between these last two layers, a diffusion barrier layer protecting against diffusion of tin from the functional layer into the intermediate layer or back to the diffusion barrier layer. The diffusion barrier layer consists of a metallic material having a hexagonal crystal lattice, which material is applied by cathodic sputtering, forming a material structure that is densely packed in vacuo with a space filling by metal ions of above 70%. For the cathodic sputtering, conditions of plasma pressure and substrate temperature can be chosen so that recrystallization occurs simultaneously with the formation of the diffusion barrier layer; this makes it possible to achieve the densest hexagonal packing, with a space filling of up to 74%. Pure titanium is the preferred material for the diffusion barrier layer.